Generally, a coating apparatus for coating a work piece such as the body of an automobile is required to be able to reduce the amount of paint discarded at the time of color change and to be able to deal with numerous coating colors. As a coating apparatus for dealing with these requirements, a cartridge type coating apparatus is known which is arranged such that a cartridge with paint replenished therein is replaceably mounted on a paint spraying apparatus or a coating apparatus.
The cartridge which is used in the cartridge type coating apparatus is constituted by a tank into which paint is replenished, a feed tube whose proximal end side is mounted on the tank and whose fore distal end side extends in an axial direction from the tank, a partition wall which is provided movably in the tank and partitions an interior of the tank into a paint chamber and an extruding liquid chamber, and a paint valve for opening and closing a paint supply passage in the feed tube at a fore distal end portion of the feed tube. The cartridge allows paints of a plurality of colors to be used by effecting a color change, and is arranged such that its interior is washed clean on every occasion of the color change, and a next color paint is replenished into it.
The paint replenishing apparatus for a cartridge for replenishing paint into a cartridge is largely constituted by a cartridge support member in which a feed tube insertion hole for insertion of the feed tube therethrough is provided in such a manner as to extend in the axial direction, and in which a tank support portion for supporting the tank of the cartridge at the time of the replenishment of paint is provided on a side of an insertion port of the feed tube insertion hole; a color change valve device which is provided by being connected to the cartridge support member, and which supplies a paint selected from among paints of a plurality of colors into the paint chamber of the cartridge and the paint supply passage of the feed tube at the time of the replenishment of paint, and supplies a wash fluid into the paint supply passage of the feed tube through the paint chamber at the time of washing off of remaining paint; an extruding liquid supply and discharge device which is provided by being connected to the cartridge support member, and which supplies the extruding liquid toward the extruding liquid chamber of the cartridge at the time of the washing and discharges the extruding liquid from the extruding liquid chamber at the time of the replenishment of paint; a waste liquid passage having one end side provided in communication with the feed tube insertion hole by being located on a bottom side of the feed tube insertion hole of the cartridge support member and another end side communicating with a waste liquid tank; a waste liquid passage on-off valve which is provided in the waste liquid passage to open and close the waste liquid passage; and a wash fluid supply device which is provided by being connected to the waste liquid passage and located on an outlet side of the waste liquid passage on-off valve and supplies a wash fluid for washing clean the waste liquid passage.
In the replenishment operation of replenishing paint into the cartridge by the paint replenishing apparatus for a cartridge, a used cartridge is mounted on the tank support portion of the cartridge support member, and a previous color paint remaining in the paint chamber of the cartridge is discharged to the side of the waste liquid passage connected to the discharge side of the feed tube. Next, a wash fluid is supplied from the color change valve device to wash off the previous color paint attached to the paint chamber of the cartridge and paint supply passage of the feed tube. Subsequently, a next color paint is supplied from the color change valve device, and is replenished into the paint chamber of the cartridge and the paint supply passage of the feed tube (for example, see Patent Document 1 and Patent Document 2).